UV absorption of Criegee intermediates: quantitative cross sections from high-level ab initio theory

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F18%3A43916691" target="_blank" >RIV/60461373:22340/18:43916691 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2018/cp/c8cp00199e/unauth#!divAbstract" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2018/cp/c8cp00199e/unauth#!divAbstract</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c8cp00199e" target="_blank" >10.1039/c8cp00199e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

UV absorption of Criegee intermediates: quantitative cross sections from high-level ab initio theory

Popis výsledku v původním jazyce

Criegee intermediates (CIs) are increasingly recognized as important intermediates in atmospheric and combustion chemistry. Modelling in these fields requires reliable characterization of the CI&apos;s UV absorption cross sections. Different experimental approaches provided seemingly contradictory results both for the simplest CI as well as for higher analogues. To resolve these discrepancies, we model simultaneously the positions, widths, shapes and absolute intensities of the first absorption bands of CIs using the semiclassical reflection principle approach based on the path integral molecular dynamics. The UV spectra were efficiently processed via the kernel density estimation method. We show that the multireference character complicates the description of the system and the appropriate treatment of the electron correlation is vital. Multi-reference methods with dynamical correlation are problematic due to high sensitivity of the results with respect to the active space. Single-reference based methods become reliable once the triple excitations components are included. Interestingly, the very similar CC2 and ADC(2) methods provide highly conflicting results which are, however, reconciled at the CC3 and ADC(3) levels. To calculate the spectra of higher CIs, we introduce composite EOM-CCSD/T and CC2/3 methods providing excellent absorption cross sections at an acceptable computational cost. We provide the first absolute intensities for individual conformers of the CH3CHOO molecule.

Název v anglickém jazyce

UV absorption of Criegee intermediates: quantitative cross sections from high-level ab initio theory

Popis výsledku anglicky

Criegee intermediates (CIs) are increasingly recognized as important intermediates in atmospheric and combustion chemistry. Modelling in these fields requires reliable characterization of the CI&apos;s UV absorption cross sections. Different experimental approaches provided seemingly contradictory results both for the simplest CI as well as for higher analogues. To resolve these discrepancies, we model simultaneously the positions, widths, shapes and absolute intensities of the first absorption bands of CIs using the semiclassical reflection principle approach based on the path integral molecular dynamics. The UV spectra were efficiently processed via the kernel density estimation method. We show that the multireference character complicates the description of the system and the appropriate treatment of the electron correlation is vital. Multi-reference methods with dynamical correlation are problematic due to high sensitivity of the results with respect to the active space. Single-reference based methods become reliable once the triple excitations components are included. Interestingly, the very similar CC2 and ADC(2) methods provide highly conflicting results which are, however, reconciled at the CC3 and ADC(3) levels. To calculate the spectra of higher CIs, we introduce composite EOM-CCSD/T and CC2/3 methods providing excellent absorption cross sections at an acceptable computational cost. We provide the first absolute intensities for individual conformers of the CH3CHOO molecule.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA17-04068S" target="_blank" >GA17-04068S: Molekulové klastry jako nano-reaktory pro chemii řízenou fotony a elektrony</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

20

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

10

Strana od-do

6421-6430

Kód UT WoS článku

000429280100043

EID výsledku v databázi Scopus

2-s2.0-85042799519